In archery bows, customization and adjustability are highly prized features. Skilled archers take advantage of even small adjustments to the weight, size, and position of various elements of the bow to improve their accuracy and precision. One part of the bow that is greatly affected by fine adjustments is the bow's limbs. The limbs are the flexible members that are usually attached to the upper and lower ends of the handle riser of the bow in limb pockets. The limbs are usually secured to the bow by bolts such as dovetail bolts and tiller bolts.
A tiller bolt extends through an opening in the proximal end of the limb to retain the limb in the limb pocket. When a tiller bolt is adjusted, the limb moves forward or backward relative to the riser. A bow's “tiller” is defined as the difference in the perpendicular distance from the upper limb to the string and the lower limb to the string, as measured at the base of the limbs where they attach to the riser. Controlling the tiller may allow the archer to more easily and comfortably aim during the draw and release of the shot. The tiller also affects the angle at which the arrow is launched from the bow when the arrow is released.
Dovetail bolts extend toward the riser from the proximal end of the limb to mate with dovetail openings in the end structure of the limb pocket and/or a dowel that is attached to the riser. The dovetail bolt is used to keep the limb from falling out of the limb pocket and, in bows using dowels, to fix the limb's position relative to the dowel's main cylinder. In bows with dowels, the lateral position of the limb may be adjusted to the left and right relative to the riser by adjusting the dowel. When adjusted, the main cylinder of the dowel moves left and right within the riser, thus causing the dovetail bolt and the limb to which it is connected to move left and right as well. The limb's motion may be lateral translation or may be a rotation of the vertical axis of the limb to the left or right, depending on whether the limb is pivotally connected proximal to the dowel in the limb pocket. By adjusting the lateral position of the limb, the bowstring may be moved left and right at the distal end of the limb, so the archer may adjust the alignment of the bowstring relative to the riser and the arrow plane.
Conventional methods of adjusting the position of the limb relative to a riser only control the left-right lateral position of the limb or the front-back lateral position of the limb. This limits the amount of control the archer has over the tuning of his or her bow limbs. Therefore, there exists a need for improvements in archery bow limb tuning, particularly in positioning a riser relative to a limb.